Study shows that adulterous monkeys hide their sexual affairs

As humans, it's common knowledge that having an affair is taboo -- something that should clearly be kept secret -- but a recent study shows that macaque monkeys think of sexual affairs as being taboo, too.

In groups that include alpha male monkeys, some of the monkeys who are lower on the totem pole have been found to sneak around outside of their monogamous relationships.

While high-ranking males have dibs on mating with the females in the group, females have been known to give non-alpha males a chance too, with these interactions happening most commonly when alpha males are out of sight.

Monkeys are known to deceive each other on a basic level, but recent evidence shows that many monkeys go far beyond that foundational level of deceit.

Researchers in the Netherlands found that in situations where there is food competition, monkeys preferred to grab a small piece of food when a dominant monkey wasn't looking.

After hearing of this research, Utrecht University scientist Anne Overduin-de Vries decided to test monkeys sneaky skills in situations that pertain to sexual interactions.

Observers spent hundreds of hours watching groups of monkeys, recording all movements, with nearly a thousand of those actions pertaining to sexuality.

When the monkeys would sexually interact with monkeys that weren't the usual alpha male, they would act distant, moving farther away from the alpha males.

The research shows that not only do the monkeys know what they're doing sexually, but they know how to be sneaky about it, too.

Monkeys can be sneaky, but they can be giving, too. See the adorable video below of a monkey who insists on sharing his food with a human: